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Additional Photos
underside
side
sensory bristles
purple "tails"
dark
white
spots & "flares"
young
attacking prey
predation
mating
shell
egg mass
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GALLERY
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Philinopsis speciosa Pease, 1860
Maximum size: about 76
mm (Hoover, 2006).
Identification:
This
is
a
flattened,
sand-dwelling species that is highly variable in
color. Light animals are usually cream to light brown shading to dark
brown near the margin. They usually have a fine, bluish-white marginal
line and are mottled with orange and white. Often, there is a
purple patch on the "tails." Dark animals are velvet-black
margined in blue but various intergrades are common. Occasional animals
may be white with violet-tipped "tails."
Natural history:
Philinopsis speciosa
is a common animal found in open sand and Halimeda kanaloana beds at depths
of 9-27 m (29-90 ft). Occasionally, it may also be found in mixed
habitats at moderately exposed to highly exposed sites in depths of as
little at 1 m (3
ft).
Mature animals are usually nocturnal but younger ones may sometimes be
seen in numbers crawling on the surface
by day, particularly in Halimeda
kanaloana beds. It feeds on sand dwelling haminoeids. (Note 1)
It has also been observed eating the sea hare, Stylocheilus striatus by Mike
Roberts (Sea Slug
Forum) and Rebecca Bicker (see photos). Its egg mass is an elongate, white sack composed of a
tangled egg
string. Egg masses are typically anchored in sand and are often found
in pairs suggesting that both animals in a mating pair may lay before
separating.
Distribution:
Big Island, Maui, Oahu and Kauai: widely distributed in the Indo-Pacific; also in the Eastern Pacific.
Taxonomic notes:
It
is
referred
to
as the "blue headshield slug" in Hoover, 1998 and the
"blue-margin headshield slug" in Hoover, 2006. It was first reported
from Hawaii in Pease, 1860. Philinopsis cyanea is a synonym. (Gosliner, et. al., 2008) It's listed as Aglaja speciosa in Pilsbry, 1921 and Edmondson, 1946.
Photo: CP: 60
mm: Hekili Point, Maui; Nov. 14, 2008.
Observations and comments:
Note
1: A 15 mm animal brought in on
April 28, 2005 was held in a dish with a sand bottom for several days.
It regurgitated the shell of a small Aliculastrum
debile one day later confirming that it had eaten that species
in the field. When offered a somewhat larger A. debile it "half-engulfed" the Aliculastrum but the latter broke free with
vigorous swimming motions and remained uneaten in the dish for several
days. When offered a small Atys pittmani, the Philinopsis
ate it immediately, regurgitating the shell by the following day. When
offered a small Liloa curta,
it rejected the animal when it was presented "head first" but
successfully ate it when it was offered "tail first." Again, it
regurgitated the shell by the following day.
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